078
FXUS65 KBYZ 271036
AFDBYZ
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE BILLINGS MT
436 AM MDT SAT JUN 27 2026
KEY MESSAGES
- SEVERE THUNDERSTORMS ARE EXPECTED TO IMPACT MUCH OF THE AREA
TODAY. THERE IS A RISK LEVEL 3 OF 5 FOR SEVERE STORMS EAST OF
ROSEBUD COUNTY. MAIN HAZARDS ARE LARGE HAIL AND STRONG WIND
GUSTS WITH HEAVY RAIN BEING A SECONDARY THREAT.
- SHOWERS AND THUNDERSTORMS AGAIN SUNDAY. SEVERE STORMS ARE NOT
EXPECTED.
- SNOW IS LIKELY IN THE MOUNTAINS ABOVE 8300 FEET SATURDAY NIGHT
INTO SUNDAY NIGHT, WITH ACCUMULATIONS OF 1-2".
- WARMING AND DRYING TREND NEXT WEEK.
UPDATE
UPDATED FORECAST TO ACCOUNT FOR THE LINE OF SHOWERS AND
THUNDERSTORMS FROM NEAR FT.SMITH NORTH TO AROUND INGOMAR. THE LINE
IS DRIFTING SLOWLY TO THE EAST WHILE INDIVIDUAL CELLS ALONG THE
LINE ARE MOVING NORTH-NORTHEAST. LATEST HRRR HAS CAUGHT ON TO THIS
FEATURE AND LIFTS THIS ACTIVITY NORTH OF THE AREA BY 7AM, BUT
THEN ANOTHER LINE BEGINS TO TAKE SHAPE ALONG THE SAME PATH,
BUILDING FROM THE SOUTH THROUGH MID MORNING. THIS ACTIVITY IS
ALONG A NEAR SURFACE CONVERGENCE BOUNDARY BETWEEN NORTHWESTERLY
WINDS TO THE WEST AND SOUTHEASTERLY WINDS TO THE EAST INTERACTING
WITH JET DYNAMICS FLOWING UP AND OVER THE AREA FROM THE SOUTH.
ACCELERATED THE INGRESS OF PRECIPITATION CHANCES FROM THE WEST
THIS MORNING TO ACCOUNT FOR THE ACTIVITY NOW EXPECTED INTO CENTRAL
ZONES. UPDATED THE FORECAST TO REFLECT THE SEVERE THREAT AREA FOR
THIS AFTERNOON AND EVENING. MODELS CONTINUE TO SHOW SEVERAL
STRONG HELICITY TRACKS OVER THE EASTERN HALF OF THE FORECAST AREA,
GETTING GOING AROUND NOON-1PM OVER THE PRYOR/BIGHORN MOUNTAINS
AND MOVING NORTHEASTWARD THROUGH EARLY EVENING. THE MAIN THREATS
IN THE ENHANCED RISK AREA WILL BE GOLF BALL SIZE HAIL AND WIND
GUSTS TO AROUND 70 MPH. HIGH PWATS WILL ALSO SUPPORT LOCALLY HEAVY
RAINFALL, THOUGH QUICK STORM MOTION SHOULD LIMIT THE FLASH FLOOD
THREAT. REST OF THE FORECAST ON TRACK. IF YOU HAVE OUTDOOR PLANS
TODAY PLEASE STAY WEATHER AWARE AND HAVE A PLAN TO QUICKLY FIND
SHELTER SHOULD STORMS APPROACH YOUR LOCATION. CHAMBERS
DISCUSSION
THROUGH NEXT SATURDAY...
THE STORM PREDICTION CENTER HAS ISSUED A LEVEL 3 OUT OF 5 THREAT
FOR SEVERE STORMS FOR LOCATIONS EAST OF ROSEBUD COUNTY TODAY. THE
THREAT DECREASES TO THE WEST WITH LOCATIONS FROM BILLINGS WEST
BEING IN A LEVEL 1 OF 5 THREAT. 500 MB TROUGHING TO OUR WEST WILL
CREATE SURFACE LOW PRESSURE OVER WYOMING HELPING TO ADVECT
MOISTURE INTO THE REGION BEFORE BRINGING A COLD FRONT THROUGH IN
THE AFTERNOON. HRRR SOUNDINGS INDICATE STRONG CAPPING IN THE
MORNING BEING OVERCOME BY STRONG LOW AND MID LEVEL LAPSE RATES BY
EARLY AFTERNOON. STRONG INSTABILITY IS EXPECTED IN THE HIGHEST
RISK AREAS WITH CAPE VALUES IN THE 1-2,000 J/KG RANGE AND 0-6 KM
SHEAR IN THE 40-50 KT RANGE.
MODELS ARE TURNING THESE ENVIRONMENTAL FACTORS INTO STRONG STORMS
FOR MUCH OF THE AREA. THE LATEST HREF RUN SHOWS HELICITY TRACKS
MOVING OFF THE BIGHORN MOUNTAINS AND STRENGTHENING OVER SOUTHEAST
MONTANA. THE SOUTHWEST TO NORTHEAST SHEAR PROFILES THAT ARE
EXPECTED TODAY INDICATE STORMS STARTING OUT DISCRETE BEFORE
EVOLVING INTO MCS LIKE STRUCTURES. SOME DETERMINISTIC MODELS SUCH
AS THE HRRR INDICATE A BOWING MCS STRUCTURE OVER SOUTHEAST MONTANA
BRINGING WIND GUSTS IN EXCESS OF 50 KTS. ALL WEATHER THREATS WILL
BE IN PLAY TOMORROW INCLUDING WEAK TORNADOES, HAIL >2.0 INCHES,
WIND GUSTS >70 MPH, AND HEAVY RAIN.
SUNDAY WILL SEE CHANCES (40-60%) FOR SHOWERS AND THUNDERSTORMS
NORTH AND WEST OF A LINE FROM RED LODGE TO MILES CITY. SEVERE
STORMS ARE NOT LIKELY. PRECIPITATION CHANCES (40-70%) LINGER
MONDAY WITH SHOWERS AND GENERAL THUNDERSTORMS EXPECTED. SNOW
LEVELS ARE EXPECTED TO GET LOW ENOUGH (~8,000 FT) SUNDAY AND
MONDAY TO ALLOW 1-2 INCHES OF SNOW TO ACCUMULATE IN THE
ABSAROKA/BEARTOOTH MOUNTAINS. TUESDAY THROUGH SATURDAY IS EXPECTED
TO BE WARMER AND DRIER WITH TEMPERATURES INCREASING FROM THE 60S
AND 70S F SUNDAY AND MONDAY TO THE 80S F BY WEDNESDAY. TORGERSON
AVIATION
10Z DISCUSSION....A FEW LINES OF SCATTERED SHOWERS AND
THUNDERSTORMS WILL CONTINUE THROUGH THIS MORNING, TRACKING
SOUTHWEST TO NORTHEAST ACROSS MAINLY THE WESTERN AND CENTRAL
PORTION OF THE FORECAST AREA. THE MAIN THREAT WITH THIS ACTIVITY
WILL BE LOCALIZED WIND GUSTS TO 35KTS AND BRIEF HEAVY DOWNPOURS,
BUT DO NOT EXPECT REDUCTIONS IN FLIGHT CATEGORY BELOW VFR. UPPER
LEVEL STORM SYSTEM PUSHES CLOSE ENOUGH TO THE AREA BY LATE MORNING
TO GENERATE MORE WIDESPREAD SHOWER AND THUNDERSTORM ACTIVITY,
STARTING IN THE WEST AND SPREADING EASTWARD THROUGH THE DAY. MVFR
CEILINGS AND VISIBILITY DOWN TO 2SM ARE FORECAST WITH THE HEAVIER
SHOWERS/THUNDERSTORMS THROUGH MID EVENING. THERE IS AN ENHANCED
RISK FOR SEVERE STORMS OVER SE MT STARTING AROUND 20Z WITH GOLF
BALL SIZE HAIL AND GUSTS OVER 60KTS, ALONG WITH TORRENTIAL
RAINFALL, THE MAIN THREATS. A JET INDUCED DRY SLOT PUNCHES UP INTO
THE AREA FROM THE SOUTH MID EVENING PUSHING STRONG CONVECTION
NORTHEAST OF THE AREA AND LEAVING MAINLY DRY VFR CONDITIONS,
OUTSIDE OF THE IMMEDIATE WESTERN FOOTHILLS (KLVM) AND MOUNTAINS
WHERE SHOWER ACTIVITY WILL LIKELY PERSIST THROUGH TONIGHT.
CHAMBERS
PRELIMINARY POINT TEMP/POPS
TDY SUN MON TUE WED THU FRI
-------------------------------------------------------
BIL 074 052/068 049/068 051/077 052/081 055/087 059/089
9/T 82/T 25/W 31/U 12/T 10/B 11/B
LVM 066 042/058 040/058 041/071 043/076 046/081 049/082
8/T 96/T 78/T 53/T 23/T 32/T 22/T
HDN 077 050/072 047/071 049/078 050/083 053/090 057/091
8/T 81/N 26/W 21/U 11/B 11/U 11/U
MLS 081 054/073 050/071 052/077 053/083 056/090 061/092
5/T 72/N 15/W 21/U 11/B 10/U 11/U
4BQ 080 054/075 051/074 052/078 053/084 057/091 061/095
6/T 41/B 24/W 11/U 11/U 11/U 11/U
BHK 085 052/076 049/073 049/077 051/084 054/089 058/093
3/T 51/B 44/T 21/N 12/T 11/U 11/U
SHR 073 046/072 044/072 045/075 046/081 050/088 054/091
7/T 52/B 33/W 12/T 12/T 01/U 01/U
BYZ WATCHES/WARNINGS/ADVISORIES
MT...NONE.
WY...NONE.
WEATHER.GOV/BILLINGS
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page